diff --git a/yaml/tojson.nim b/yaml/tojson.nim
index 76bd59a..6dafd45 100644
--- a/yaml/tojson.nim
+++ b/yaml/tojson.nim
@@ -142,7 +142,6 @@ proc constructJson*(s: var YamlStream): seq[JsonNode]
           let jsonScalar = jsonFromScalar(event.scalarContent,
                                           event.scalarTag)
           levels[levels.high].node[levels[levels.high].key] = jsonScalar
-          levels[levels.high].key = ""
           levels[levels.high].expKey = true
           if event.scalarAnchor != yAnchorNone:
             anchors[event.scalarAnchor] = jsonScalar
@@ -154,12 +153,11 @@ proc constructJson*(s: var YamlStream): seq[JsonNode]
         case levels[levels.high].node.kind
         of JArray: levels[levels.high].node.elems.add(level.node)
         of JObject:
-          if levels[levels.high].key.len == 0:
+          if levels[levels.high].expKey:
             raise newException(YamlConstructionError,
                 "non-scalar as key not allowed in JSON")
           else:
             levels[levels.high].node[levels[levels.high].key] = level.node
-            levels[levels.high].key = ""
             levels[levels.high].expKey = true
         else:
           internalError("Unexpected node kind: " &
@@ -173,13 +171,12 @@ proc constructJson*(s: var YamlStream): seq[JsonNode]
         levels[levels.high].node.elems.add(
             anchors.getOrDefault(event.aliasTarget))
       of JObject:
-        if levels[levels.high].key.len == 0:
+        if levels[levels.high].expKey:
           raise newException(YamlConstructionError,
               "cannot use alias node as key in JSON")
         else:
           levels[levels.high].node.fields.add(
               levels[levels.high].key, anchors.getOrDefault(event.aliasTarget))
-          levels[levels.high].key = ""
           levels[levels.high].expKey = true
       else:
         internalError("Unexpected node kind: " & $levels[levels.high].node.kind)